Revenge of the Restaurant

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

Revenge of the Restaurant

Dinner is exciting when you’re hungry — but it can get a lot more exciting if you eat at any of the strangest restaurants in America. There was a restaurant decorated like a bathroom, where you sit on a toilet to eat (shown here). If that doesn’t sound good to you, other people agree, because it did go out of business. But you can still go to Harvey Washbangers, where you can do your laundry while you eat, and a giant board shows when your clothes have finished. You can eat with spies at the Safe House, or try Ninja New York, where your meal is served by ninjas who yell, wave swords, and do backflips. In all cases, your meal might be the least exciting part!

Wee ones: How many toilets can you count in the photo?

Little kids: If 3 ninjas take turns bringing you dishes in the same repeating order, and you order 5 dishes, how many times at most can any one ninja serve you? Bonus: If 10 ninjas work there and every other one can do backflips, how many backflipping ninjas are there?

Big kids: If at Harvey Washbangers it takes 32 minutes to wash your clothes and 25 to dry them, do you have a whole hour to eat dinner? Bonus: At Fritz’s Railroad Restaurant, your food is brought to you by a toy train on tracks above your head. If the train comes by every 12 minutes, how many times can it come by at most in 80 minutes?

The sky’s the limit: If you want to try eating in a bathroom, a laundromat, a ninja cave and a spy cave, in how many orders can you try those 4 restaurants?

Answers:Wee ones: 4 toilets.

Little kids: 2 times at most. Bonus: 5 ninjas.

Big kids: Not quite, as that will all take just 57 minutes. Bonus: 7 trips. If it comes at every multiple of 12 (12, 24, 36, 48, 60, 72), that gives you 6 trips…but if the train first visits at minute 1 and then 1 minute later than each of these times, it will fit 7 trips.

The sky’s the limit: 24 orders. If the restaurants are B, L, N, S, you have 4 choices for your first meal. Once you go there, you have only 3 choices for your 2nd meal for each of those 4 1st choices, giving you 4 x 3 pairs. Then for your 3rd meal, you have only 2 choices left for any of your first 12 pairs. After that, there’s always only one choice left. That gives you 4x3x2x1 = 24. If you want to see the choices, they are BLNS, BLSN, BNLS, BNSL, BSLN, BSNL, giving 6 orders that start with the bathroom…then repeat this for each of the other 3 restaurants as your first!

About the Author

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking while still in diapers, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.